Verifying software in the brake control system of Boeing's 787 Dreamliner is the latest problem.

FARNBOROUGH (Reuters) - Verifying software in the brake control system of Boeing's (BA.N: Quote, Profile, Research, Stock Buzz) 787 Dreamliner is the latest problem holding back the new plane's first test flight, the troubled program's chief said.

The first of the 787s, originally meant to fly last summer, has been
held back by three major production delays due to parts shortages and
incomplete work from suppliers arriving at its assembly plant near
Seattle.

The plane is still on track for a first flight in the fourth quarter
-- in line with the last schedule announced in April -- but the newest
"air bubble" in the timetable is in the brake systems, Pat Shanahan,
general manager of the 787 program, said at a briefing at Farnborough
Airshow on Tuesday.

"We need to push harder on the brake system," he said.

If all had gone to plan in production, the sleek, fuel-efficient
airliner would have been one the stars of the world's largest air show
after being delivered to its first Japanese customer in May.

Shanahan confirmed the plane is still on track for first delivery in the third quarter of 2009, Boeing's latest target.

But Boeing has suffered parts shortages and problems with incomplete
work by suppliers, resulting in delivery delays resembling the two-year
lag encountered by Airbus on its A380 superjumbo, which entered service
last October.

In the latest hitch, there have been delays getting the software in
the 787's brake control system verified to meet stringent certification
requirements, said Shanahan, who has led the 787 program since October
last year.

"It's not that the brakes don't work, it's the traceability of the
software," Shanahan said, explaining that Crane had to go back and
rewrite certain parts of the brake control software to verify it for
the certification process.

"I'm confident it will be done. It's General Electric," Shanahan said.

Crane officials at the show declined to comment. The company's official spokeswoman was not immediately available.

The French company providing wheels and other parts of the braking
system, as well as the carbon brakes themselves, said it had nothing to
do with any of the problems cited by Boeing.

The wheels and brakes are provided by Messier-Bugatti, a unit of French conglomerate Safran (SAF.PA: Quote, Profile, Research, Stock Buzz). A sister company, Sagem Defense and Security, provides an electrical braking system known as the EBAC.

"Our material has passed 'Safety of Flight' tests and has been
delivered in its entirety for the first flight. It also passed the
recent 'Power On' tests on the 787," Messier-Bugatti President
Jean-Christophe Corde told Reuters.

"Airplane One is in really good shape," said Shanahan, who replaced
Mike Bair, the original 787 chief, after the first major delay on the
plane last year.

He conceded that along with the brake system problem, more work
needs to be done on the mid-body of the first plane and there were
still parts shortages on the wing.

Boeing's next steps are putting hydraulics on the first plane and
running the engines, as it moves toward first flight in the fourth
quarter, Shanahan said.

However, Airplane 4, which will also be used for flight tests, could
pose the next problem. The main fuselage of that plane is still at the
Global Aeronautica plant in South Carolina, two to three weeks after it
was due to be shipped to Seattle for final assembly.

That delay did not directly threaten the flight test timetable, but
was eating away at extra time built in to the schedule, said Shanahan.
"I'm eating margin I don't want to eat."

Global Aeronautica, a joint venture between Boeing and Alenia, a unit of Italian aerospace company Finmeccanica (SIFI.MI: Quote, Profile, Research, Stock Buzz),
is putting together the main parts of the plane's body's fuselage at a
specially built facility in Charleston, South Carolina.